With a 5.2in display, Ultra HD 4K video recording, and the same waterproof design as its popular Xperia Z1 predecessor, Sony describes the new addition to the Z2 family as its "best ever premium waterproof smartphone".

On the outside, it would be hard to tell the Z2 and the Z1 apart. Both phones share a metal chassis, sleek but hard-wearing design, and waterproofing. But the Z2, launched only five months after its predecessor, improves on just about every aspect where the previous model fell short.

The Xperia Z2 has taken its display up a notch. Not only is it 0.2in larger at 5.2in compared to the 5in screen on the Xperia Z1, but Sony has also introduced Live Colour LED to the Trimluminos and X-Reality tech of the Xperia Z1.

While the resolution stays the same at 1920 x 1080 pixels, the Live Colour LED technology is said to widen the spectrum of available colours, allowing you to boost the screen's colour without oversaturation.

The phone has also got considerably slimmer. The Xperia Z2 is 8.2mm thick while the Xperia Z1 was a hefty 144.4 x 73.9 x 8.5mm.

"With Xperia Z2 we have taken our premium Z series to the next level, delivering unique experiences that only Sony can offer," said Kunimasa Suzuki, President and CEO, Sony Mobile Communications.

"We have redefined the smartphone once again through our camera. Xperia Z2 offers an innovative experience that captures memories in stunning detail through 4K video shooting, or offers new ways to use the camera with our unique Xperia camera apps."